NCEDC Blog

The NCEDC has extented its continuous archive of 250 Hz data from the HRSN (BP) network with an additional 109 days of continuous 250 Hz data. Continuous 250 Hz data from 2002.228,20:00 - 2002.336,20:00 now available from the HRSN (BP) network in addition to the event-triggered 250 Hz data archive.

The HRSN normally archive continuous 20 Hz data (channels BP1, BP2, and BP3) and low frequency state-of-health (SOH) channels from the HRSN network in addition to the event-triggered 250 Hz data channels DP1, DP2, and DP3. However, continuously recorded DP1, DP2, and DP3 data channels are now available for days 2002.229,20:00 through 2002.337,20:00.

Due to telemetry problems, the 250 Hz channels for some stations and days is highly fragmented. The following table shows, for various timespans, the number of discrete time segments in the raw data that are greater than that timespan. In order to reduce the number of extremely small time segments for normal users of these data channels, the NCEDC removed any discrete timeseries segment that was less than 20 seconds in duration in its normal archive and database descriptor tables.

The full timeseries for these days, however, are available on request from the NCEDC.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

The NCEDC is gradually converting the Northern California earthquake catalogs from "flat files" to a database structure. At present, the BSL BDSN catalog is transferred from 1984-present and the information is accessible through a search interface here:

As part of this conversion, the "flat file" search of the BSL catalog available here is no longer being kept up to date. Please access the new database search for access to the most current catalog from the BSL.

We are currently working to convert the USGS earthquake catalog to the database structure. This should be available in the next few months.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

The NCEDC resolved software problems associated with the computation of magnetic activity and Schumann resonance. Computations resumed in July 2003 and are ongoing. We apologize for the late notification!

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

During a computer upgrade at the NCEDC, the disk drive holding the current queue of NetDC, BREQ_FAST, and EVT_FAST request died. We restored the filesystem from backup tapes, but are unable to recover any unprocessed requests. If you recently submitted a request for data and did not receive a reply with the data's URL for pickup, please resubmit your request.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.

The BDSN and MiniPBO Q4120 Quanterras will be reconfigured and rebooted at 5 pm PST today (July 1, 00:00 UTC) in order to change the FIR filter for the 100 Hz channels from acausal to causal. The affected stations are:

The new BDSN Q4120 station MNRC was upgraded yesterday, since it is a new station and continuous telemetry has not yet been installed.

This change is motivated by the desire to improve phase picking on the 100 Hz channels. This writeup by Bob Uhrhammer and Bob Nadeau describes how the change affects the data.

This change means that all Q4120/Q730 dataloggers operated by the BSL will use causal filters for sampling rates of 100 Hz and higher (The HRSN and NHFN have traditionally used causal filters for the higher sampling rates). Lower data rates will continue to use the acausal filters. This change does NOT apply to the BDSN sites with Q680/980 dataloggers, as they cannot be configured for causal filtering.

Updated instrument responses will be available soon.

The NCEDC is a joint project of the University of California, Berkeley and the USGS. Please send us email at ncedcinfo@ncedc.org or fill out our comments form if you have questions or comments about these changes.